If you're disappointed by the high prices announced for Nvidia's RTX 2080 and RTX 2080 Ti, cards like the Asus RTX 2080 Turbo should come in at the lower end of the announced price range. That's still a hefty $699 for the RTX 2080, and $999 for the RTX 2080 Ti, but every little bit helps. Based on initial performance data, not to mention all the new features like the RT cores and Tensor cores, demand is going to be high.
The good news is that we should see custom RTX designs not too long after the initial launch on September 20. The Asus RTX 2080 Turbo sticks with a blower for cooling as well, which might be a better choice for 2-way SLI if you don't have a large case and enough separation between the graphics cards. It's not the sexiest looking graphics card, but inside it runs the same hardware as other RTX 2080s, and that's what counts.
If you'd rather have a non-blower GPU but don't want a Founders Edition card, there will be a lot of alternatives. Asus has both standard PCB designs and custom designs coming, and other vendors will likely take a similar approach. I've seen custom RTX 2080 models from just about every graphics card vendor at Gamescom, most using existing cooler designs. The GTX 1080 and 1080 Ti have similar power and cooling requirements as the RTX models, so these coolers should be sufficient for the RTX 2080 and 2080 Ti, though how far you can overclock might vary more depending on your cooler. Most of the factory overclocked cards will probably cost as much as the Founders Edition, however, at least initially.
I've spoken with several graphics card manufacturers at Gamescom, and the expectation is that the RTX 2080 Ti and RTX 2080 Founders Edition models will sell out fast for the first month or two after launch. This has happened with nearly every major GPU launch for many years, and after two years of GTX 10-series parts, there's a lot of desire for something new and faster. If demand eclipses supply as expected, it might take a couple of months before we see any 'budget' custom cards come to market.
If the new RTX cards are too much for your wallet but you're still looking to upgrade, I also don't expect an RTX 2060 to ship in 2018. Instead, prices on the existing GTX 1070 and 1070 Ti are likely to drop into the $300 range. It sounds as though there are still a lot of 10-series cards waiting for buyers now that cryptocurrency miners aren't snapping them up, so waiting a month or two before buying a graphics card would be my advice.